How Can Soil Quality Slow Global Warming?

A new study from the University of Berkeley in California has found that improving soil quality could make a substantial contribution to slowing down global warming. What’s more, the practices needed to make this scenario a reality are already widely-practiced around the world and involve little technological or financial investment to implement.

The authors of the paper found that if simple initiatives like planting cover plants, sowing legumes and optimising grazing terrain were introduced on a worldwide scale, they could reduce global warming by as much as a quarter of a degree Celsius. If the controversial additive biochar was factored in, the reductions could amount to as much as half a degree. However, none of the above will have any meaningful impact without attendant reductions in carbon emissions.

Agriculture as hero rather than villain?

The farming industry (both in terms of cattle and crop farms) is often painted as highly detrimental to the environment. Whether it’s the land appropriation and resource consumption of crops or the methane emissions caused by cattle, farmers and agriculture often get a bad rap. However, the new study aimed to reinvent the industry as a potential saviour rather than aggressor for the plight of the planet.

“As someone who has been working on carbon sequestration for a long time, I have always had this question in the back of my mind, ‘Will sequestration in soils make a difference with climate change at a global scale?’” explained Whendee Silver, lead author on the report. “We found that there are a wide range of practices deployable on a large scale that could have a detectable worldwide impact. A big take-home message is that we know how to do this, it is achievable.”

Nothing ground-breaking

For their investigation, Silver and her colleagues analysed how practices which are already known to capture carbon in soil would affect the environment if introduced on a global scale. A key aspect of the project was to ensure that all of the methods included in the study were ones which are already well-established around the world and which would not involve significant outlay to introduce them in places where they aren’t already practiced.

The authors found that if the practices were accompanied by aggressive cutbacks in carbon emission, they could bring down global temperatures by as much as 0.26°C. When biochar (which is produced by burning leftover crops in an environment free from oxygen, and which has courted controversy in environmental circles) was involved, that figure could rise to 0.46°C.

Even more reductions possible

There is scope for soil sequestration to play an even bigger role in combatting global warming, since the paper did not take into account certain modern practices which might benefit the environment more but could place a greater strain on farmers. “The point of our paper was to look at the temperature effect of implementing existing low-tech technologies already practiced within agriculture, in developing as well as developed countries," explained Allegra Mayer, co-author on the paper. “There could theoretically be an immediate and widespread adoption of many of these practices.”

In any case, the reductions predicted by the team would be entirely impossible without a simultaneous reduction in carbon emissions. The real secret to counteracting climate change will come through robust air quality networks, sustainable methods of energy generation and a concerted effort from individuals, companies and governments to reduce our carbon footprint. Only then will we realise the targets of the COP21 Paris agreement in limiting global warming as much as possible.